The proposed research aims to develop in mouse tumor systems, principles and methods which will lead to simple, clinically useful, laboratory procedures to assay specific anti-tumor immune reactivity in cancer patients. When immune function tests become reproducible and accurate in animal models, they will be tested with human materials such as venous blood and neoplastic tissue samples. Initially, four basic methods will be used: (1) Tumor-specific lymphocyte activation (blastogenesis) determined by an assay for radioactive C14 released by the action of enzymes formed early in the lymphoblastic response; (2) tumor-specific serum activity determined by the binding of radioactive I 125 to living tumor cells; 3) tumor-specific lymphocyte and (4) serum activity determined by the release of radioactive Cr51 from labeled tumor cells. Any promising and practical new procedures originating here or elsewhere will be tested and compared with other procedures. If more than one procedure is found to be clinically useful, all such procedures will be used simultaneously in each clinical assay for greater dependability and for the purpose of comparison.